Method of manufacturing ready-to-wear crease-resistive garments

ABSTRACT

Crease-resistant properties are imparted to wash-and-wear garments by impregnating cellulosic textile fabrics with a solution of a polymeric acetal obtained by reacting formaldehyde and a polyol, together with an acid catalyst, and thereafter drying and forming a garment from the fabric, and pressing the same, the pressed finished garment then being subjected to a prolonged cure which imparts crease resistance to the garment.

O United States Patent [151 3,660,009

Sexsmith 51 May 2, 1972 [54] METHOD OF MANUFACTURING References CitedREADY-TO-WEAR CREASE-RESISTIVE UNITED STATES PATENTS GARMENTS 2,785,9483/1957 [72] Inventor: Frederick H. Sexsmith, Erie, Pa. 2,785,949 52,974,432 3/1961 173] Assignee. lrzligmaster Onyx Corporation, New York,3,409,387 1 Hm I 22] Filed: Feb. 2, 1969 Primary Examiner-George F.Lesmes Assistant ExaminerJ. Cannon 1 l. N 21 2 [2 1 App 0 8Att0rneyArthur A. Jacobs Related US. Application Data [63]Continuation-impart of Ser. No. 491,009, Sept. 28, [57] ABSTRACT 1965,abandoned. Crease-resistant properties are imparted to wash-and-weargarments by impregnating cellulosic textile fabrics with a solution of apolymeric acetal obtained by reacting formaldehyde 521 U.S. Cl ..8/116,8/1 16.4, 8/120, and a P tOgether with an acid Catalyst, and thereafter33/144 2/243 drying and forming a garment from the fabric, and pressing[51] Int. Cl ..D06m 15/10, D06m 15/44 the same. the pressed fin shedgarment then being subjected to [58] Field of Search ..8/116.4, 1 16,120; 38/ 144; a prolonged cure which imparts crease resistance to thegar- 2/243 ment.

8 Claims, No Drawings METHOD OF MANUFACTURING READY-TO-WEARCREASE-RESISTIVE GARMENTS This is a continuation-in-part of co-pendingapplication Ser. No. 491,009, filed Sept. 28, 1965, now abandoned.

This invention relates to the method of manufacturing ready-to-wear,crease-retentive garments. The method comprises treating a cellulosicfabric with a specific type of polymeric acetal, drying the fabric,forming a garment from such treated fabric, and then subjecting thegarment to a prolonged cure, thereby imparting to the fabric acrease-recovery angle of at least about 260.

lt is known in the art that fabrics may be rendered substantiallycrease-retentive by applying a resinous prepolymer to the fabric, andthen curing the fabric at an elevated temperature. Frequently, theresinous prepolymers which are used are urea-formaldehyde,melamine-formaldehyde, and the like.

These polymeric finishes, however, suffer from several serious defects.For example, they absorb chlorine from the bleachers which are commonlyused in laundering. Accordingly, evolution of hypochlorous orhydrochloric acid occurs when the fabric is ironed, pressed, orotherwise subjected to heat treatment. The acid weakens the fabric andeventually disintegrates it. The polymeric finishes also frequentlycause yellowing of the fabric.

Whether or not such treated fabrics are bleached, the finishes tend todecompose in part after laundering and ironing, thereby liberatingsubstances with a pronounced offensive and persistent fish-like odor.These odors, as well as that of formaldehyde, are also encountered inthe curing of the finish, and these odors constitute an industrialnuisance or hazard. While such odors are removed by ventilation duringcooling, they very often reappear when the goods or fabrics have beenstored for any length of time. Such goods meet with poor commercialacceptance.

In addition to wrinkle-resistance, it is often desirable to form apermanent crease in a garment, for example, the seams of trousers, orpleats, so that such garments will not require pressing after eachlaundering. A delayed cure method for forming permanent creases ingarments is described in US. Pat. No. 2,974,432. Briefly, that processconsists of impregnating a fabric with a solution of a polymerizableresin, partially drying the fabric below the curing temperature, makingthe fabric into a garment, ironing or pressing the garment to its finaldesired shape, and then applying heat to the garment to cure thethermosetting resin impregnated therein. The garment produced by thisprocess is wrinkle-proof and retains the creases initially formed in it.

Such a process has not been entirely successful, however, because thethermosetting resins employed therein frequently possess the undesirablequalities described above, that is, they tend to retain chlorine whenthe fabric is bleached. They tend to cure permaturely while they arestored and they tend to give off unpleasant odors. Moreover, after thefabric is impregnated with the thermosetting resin, it is necessary tomaintain a certain amount of moisture in the fabric when it is dried soas to avoid premature curing. Therefore, when the fabric is dried, it isessential that the drying process be carried out under very carefullycontrolled conditions so as to avoid overdrying and pre-curing. Usuallyabout 2-8 percent of moisture must be retained.

it is also known in the an that a wide variety of acetal re agents canbe used to impregnate cellulosic fabrics so as to impart dimensionalstability to the fabric. It is equally well known from US Pat. No.2,785,947, that such treatment of cellulosic fabrics with acetalsimproves the crease-resistance of the fabric. Special surface effects,such as embossing, may be achieved in such acetal-treated textilematerials. Such a process has not been employed in the production ofwashwear fabrics, however, because of the unsatisfactory wrinklerecovery of the fabric, and the undesirable yellowing of the fabric. Inmany instances, and with many acetals, either the expense is prohibitiveor too many problems are encountered because of volatilization of theacetal.

It has now been found, however, that wash-wear garments, and the like,exhibiting excellent properties of wrinkle-resistance andcrease-retention, can be prepared by treating cellulosic or partlycellulosic fabrics with specific polymeric acetal reagents, drying thefabric, preparing garments from the treated fabrics, pressing or ironingthe garments so they are creased as desired, and then subjecting thegarments to prolonged cure at elevated temperatures so as to achieve acrease-recovery angle of at least about 260, as measured by the standardwrinkle-recovery tester method employed in the textile industry. Thismethod is the Tentative Test Method 55-1959T, as appears in theTechnical Manual of the American Association of Textile Chemists andColorists, (1964), Part ll, pp. Bl43-4. The wrinkle-recovery property ofa fabric is measured in terms of its crease-recovery angle.

This wrinkle-recovery tester method measures the wrinkle recovery of afabric quite accurately. Briefly described, test specimens of the sizeof 1.5 X 4 cm. are cut from a fabric to be tested. The long dimensioncorresponds to the direction of the test. These specimens are preparedby cutting in both the warp and filling directions. Generally, sixspecimens of each are used to obtain an average value. The specimens aremaintained for at least 24 hours in an atmosphere having a relativehumidity of 65 percent and a temperature of 70 F. The fabric is creasedunder a weight of 500 grams for 5 minutes. Five minutes after the weightis removed, the angle of recovery is measured. The maximum angle ofrecovery is 180. The angle of recovery of a specimen cut in the warpdirection is added to the angle of recovery of a specimen cut in thefilling direction in order to arrive at the final angle of recoveryvalue for the fabric. A high angle of recovery indicates good wrinklerecovery.

The process of this invention completely avoids the aforementioneddrawbacks encountered in the use of urea-formaldehyde,melamine-formaldehyde, etc., as wrinkle-proofing agents, both in themanufacture and in the use of garments treated with such reagents.Moreover, it has been found to be of considerable benefit that thepolymeric acetals employed according to the present invention are notadversely affected if the fabric is over-dried. Accordingly, thecomplicated controls that are ordinarily required with the usualimpregnating compounds, to prevent over-drying and pre-curing, can beavoided.

The polymeric acetal reagents which are used according to this inventionare prepared by reacting formaldehyde with a Water-soluble polyol in thepresence of an acid catalyst according to well-known methods. Thesepolyacetals are watersoluble and have a boiling point of at least about300 F. For the purposes of this invention, the term for-rnaldehyde"includes the common formaldehyde derivatives, namely, paraformaldehyde,trioxymethylene, methylal, and the like. The water-soluble polyols whichmay be used include ethylene glycol, propylene glycol, butylene glycol,diethylene glycol, dipropylene glycol, dibutylene glycol, sorbitol,glycerine, mannnitol, glycol monoethers, partial esters of polyhydricalcohols, and the like.

Blends of polymeric acetals may be used as well as single polymericacetals. The acetals may be employed in combination with carbamates, asfor example, with dimethylolmethyl carbamate or dimethylol-hydroxyethylcarbamate, or with triazone resins, or with melamine-formaldehyderesins, or with polyvinyl alcohol, or with hydroxyethyl cellulose. Whenused in relatively small amounts, in the order of about 10 percent byweight of the acetal, there is neither chlorine retention damage norodor formation with either the melamine, or carbamate derivatives. Ithas been found to be particularly advantageous to employ up to about10-15 percent by weight of polyethylene or a self-crosslinking acrylicresin along with the polymeric acetals. Unusually high crease recoveryvalues are thereby achieved.

The acetals employed in the process of this invention may be prepared bymethods well known in the art. For example, a glycol andparaforrnaldehyde may be heated together in the v n r A up presence of atrace of an acid catalyst, such as sulfuric acid, methane sulfonic acid,paratoluene sulfonic acid, and the like, the dihydric alcohol and thealdehyde being in molar proportions. An azeotropic vehicle, such asbenzene, toluene, xylene, ethyl benzene, is employed. By the use ofazeotropic distillation, one mol of water is removed and the reactionproceeds essentially to completion in good yield. After neutralizing theacid catalyst with dilute caustic, and stripping 013' the toluene orother solvent under reduced pressure, the product may be recovered as aviscous liquid, often with a tendency to crystallize.

Pad baths must contain, in addition to an appropriate acetalcomposition, a suitable curing catalyst, such as magnesium chloride,zinc sulfate, zinc nitrate, ammonium chloride, 2- amino-methyl propanolhydrochloride, oxalic acid, citric acid, and the like. These catalystsare preferably salts of strong acids and weak bases, or Lewis acids. Theacid catalyst is advantageously present in an amount of from about 5-400percent by weight of the acetal content in the bath, and the acetalcontent is from about 5 to about 40 percent by weight of the bath.Certain antioxidants, reducing agents, or oxidizing agents,sequestrants, and other auxiliaries, may also be incorporated into thefinishing bath in order to minimize thermal discoloration of thecellulose.

After the cellulosic fabric has been impregnated with the pad bathcontaining the polymeric acetal, the fabric is dried. The drying may becomplete or a small amount of moisture may be present, up to about 7-10percent, for example. Generally, this treated fabric is stored orshipped to garment manufactures, and during this period of storage, thetreated fabric does not tend to pre-cure to any undesirable extent.After the fabric has been cut and sewn so as to form the desiredgarment, the garment is pressed into a suitable shape, such as byforming creases or pleats. The garment is then subjected to a prolongedcure, that is, to a temperature between about 320 F. and 400 F. for asufiicient period of time so as to achieve a crease-recovery angle inthe fabric of at least about 260. The prolonged heating, therefore, isat a higher temperature and for a longer period of time than ordinarilywould be expected. After the polymeric acetal has apparently completelycured, the prolonged curing produces a further increase in thecrease-recovery angle of the treated fabric to a value over about 260,thereby permitting the garment to be commercially suitable forpress-free wash-wear use. If a temperature as low as 320 F, is employed,generally at least about minutes of cure time is required to produce acreaserecovery angle of 260 in the fabric.

The cellulosic textile material which can be used includes naturalcellulose or regenerated cellulose, such as hydrolyzed celluloseacetate, viscose rayon, or any suitable fabric blend having a majorportion of cellulosic material therein.

The following examples illustrate the process of the invention, but arenot intended to limit it.

EXAMPLE 1 TABLE I Crease Recovery Sample No. Curing Time Angle (W F) l1.5 minutes 244 2 10.0 minutes 261 Generally, 1.5 minutes of curing timeat 340 F. is sufficient to cure the acetal. Further curing, however,substantially increased the crease-recovery angle. Based on experience,it is generally known to the art that a minimum wrinkle recovery ofabout 260 is necessary for adequate wash-wear and pressfree performance.

EXAMPLE 2 A polymeric acetal was prepared by reacting ethylene glycolwith paraformaldehyde as described above. Finishing baths were preparedcontaining the acetal, magnesium chloride hexahydrate catalyst, and a 30percent polyethylene fabric softener.

Standard weight shirting broadcloth, scoured, bleached and mercerized,was padded through the bath to 60-70 percent wet pickup, framed, dried lis minutes at 280 F stored for 1 week, and then cured for 10 minutes at340 F. Sample swatches were tested for chlorine retention damage by thestandard test methods according to the method described in the TechnicalManual of the American Association of Textile Chemists and Colorists(1964) Damage By Chlorine Retained Standard Test Method No. 92-1962. Thefollowing results were obtained.

TABLE II Crease Chlorine Recovery Retention Sample Acetal MgCl, (W F)Damage It was noted that the finishing bath was essentially free ofdisagreeable chemical odors. Very slight amounts of formaldehyde weredetected when the treated fabric was dried and again when the samesample was cured. The finished fabric was found to have no objectionableodors. The chlorine retention damage was negligible.

EXAMPLE 3 A bath was prepared containing the diethylene glycol acetal ofExample 1, 3 percent of magnesium chloride hexahydrate, 2 percent of a30 percent polyethylene fabric softener, and 2.7 percent of a 45 percentreactive polyacrylate emulsion, The broadcloth of Example 2 was paddedto 60-70 percent wet pickup, framed, dried for l i minutes at 280 F.,stored for l week and cured for 10 minutes at 340 F., with the followingresults;

TABLE III Crease Recovery Sample No. Acetal Angle (W F) The creaserecovery was noted to be quite high.

EXANIPLE 4 TABLE IV Crease Sample Recovery Angle No. Cloth Acetal (W F)1 Cotton 6.5% 275 2 Cotton 10.0% 282 In the above Examples l-4, wherethe crease-recovery angle was measured as 260 and over, the fabrictested was capable of maintaining a pressed crease put into it beforethe curing operation even after repeated washings. Garments made fromsuch fabric are ideally suitable for press-free, crease-retentive,wash-wear use. It was also noted in the above examples that theimpregnated fabric could be substantially completely dried, i.e., to amoisture content of less than 2 percent, prior to the curing stepwithout any undesirable pre-curing of the polymeric acetals.

The invention claimed is:

1. A method of making wash-wear, press-free garments havingcrease-retention properties which comprises impregnating a cellulosictextile fabric with an aqueous solution of (a) a water-soluble polymericacetal of formaldehyde and a polyol, said acetal having a boiling pointof at least about 300 F., and being present in an amount of from about 5to 40 percent by weight of said solution, and said polyol being a memberof the group consisting of ethylene glycol, propylene glycol, butyleneglycol, diethylene glycol, dipropylene glycol, dibutylene glycol,sorbitol, glycerine, mannitol, glycol monoethers, and partial esters ofpolyhydric alcohols, and (b) an acid catalyst present in an amount offrom about 5 to 400 percent by weight of the acetal, drying the fabric,forming a garment from the fabric and pressing at least one crease intothe garment, and

then heating the garment at a temperature between about 320 F. and 400F. for a sufi'icient period of time to impart to the fabric acrease-recovery angle of at least about 260.

2. A method of making wash-wear, press-free garments havingcrease-retention properties which comprises impregnating a cellulosictextile fabric with an aqueous solution of (a) a water-soluble polymericacetal of formaldehyde and a polyol, said acetal having a boiling pointof at least about 300 F., and being present in an amount of from about 5to 40 percent by weight of said solution, and said polyol being a memberof the group consisting of ethylene glycol, propylene glycol, butyleneglycol, diethylene glycol, dipropylene glycol, dibutylene glycol,sorbitol, glycerine, mannitol, glycol monethers, and partial esters ofpolyhydric alcohols, (b) an acid catalyst present in an amount of fromabout 5 to 400 percent by weight of the acetal, and (c) from about 1-15percent, by weight of said solution, of a self-crosslinking polyacrylateresin, drying the fabric, forming a garment from the fabric and pressingat least one crease into the garment, and then heating the garment at atemperature between about 320 F. and 400 F. for a sufficient period oftime to impart to the fabric a creaserecovery angle of at least about260.

3. The method of claim 1 wherein said polyol is ethylene glycol.

4. The method of claim 1 in which the impregnated fabric is dried to amoisture content of less than about 2 percent prior to the curing of thetreated fabric.

5. The method of claim 2 in which a water-soluble polymeric acetal offormaldehyde and ethylene glycol is employed as the acetal.

6. A garment produced in accordance with the method of claim 1.

7. A garment produced in accordance with the method of claim 2.

8. A garment produced in accordance with the method of claim 3.

2. A method of making wash-wear, press-free garments havingcrease-retention properties which comprises impregnating a cellulosictextile fabric with an aqueous solution of (a) a water-soluble polymericacetal of formaldehyde and a polyol, said acetal having a boiling pointof at least about 300* F., and being present in an amount of from about5 to 40 percent by weight of said solution, and said polyol being amember of the group consisting of ethylene glycol, propylene glycol,butylene glycol, diethylene glycol, dipropylene glycol, dibutyleneglycol, sorbitol, glycerine, mannitol, glycol monethers, and partialesters of polyhydric alcohols, (b) an acid catalyst present in an amountof from about 5 to 400 percent by weight of the acetal, and (c) fromabout 1-15 percent, by weight of said solution, of a self-crosslinkingpolyacrylate resin, drying the fabric, forming a garment from the fabricand pressing at least one crease into the garment, and then heating thegarment at a temperature between about 320* F. and 400* F. for asufficient period of time to impart to the fabric a crease-recoveryangle of at least about 260*.
 3. The method of claim 1 wherein saidpolyol is ethylene glycol.
 4. The method of claim 1 in which theimpregnated fabric is dried to a moisture content of less than about 2percent prior to the curing of the treated fabric.
 5. The method ofclaim 2 in which a water-soluble polymeric acetal of formaldehyde andethylene glycol is employed as the acetal.
 6. A garment produced inaccordance with the method of claim
 1. 7. A garment produced inaccordance with the method of claim
 2. 8. A garment produced inaccordance with the method of claim 3.